(declare-fun b () (Set (Tuple String Int)))
(declare-fun c () (Set (Tuple Int String)))
(declare-fun d () (Set (Tuple String String)))
(declare-fun f () (Set Int))
(declare-fun e () Int)
(assert (= b (insert (mkTuple "" 1) (mkTuple "" 2) (singleton (mkTuple "" 4)))))
(assert (= c (insert (mkTuple 1 "1") (mkTuple 2 "2") (singleton (mkTuple 7 "")))))
(assert (= d (join b c)))
(assert (= e (card f)))
(check-sat)
